42 FOUNDATIONS OF BOTANY 
the entire root with a moderate magnifying power, since 
the whole is sufficiently translucent to allow the interior 
as well as the exterior portion to be studied while the root 
is still alive and growing. 
Place some vigorous cuttings of tradescantia or Zebrina, which 
can usually be obtained of a gardener or florist, in a beaker or jar of 
water.! The jar should 
3 ‘Oo be as thin and trans- 
5 gp = parent as possible, and 
secezenem| it is well to get a flat- 
Ea 
EER ; 
\lSeccsstmanseeem sees sided rather than a 
ERS HEE cylindrical one. Leave 
We eae tamer e ea the jar of cuttings in 
\Stssn—tBacemrs~ pela 
(Sqceceecssss tees, a sunny, warm place. 
) RR EES j ({ As soon as roots have 
Nesey ( developed at the nodes 
Sa ee / p 
and reached the length 
Auk ee YY) Pag z of three-quarters of an 
Ss 
: PA) @ 1 (l2 inch or more, arrange 
8 U decagltee a microscope in a hori- 
i~AW NOseswnyeel, zontal position (see 
WT ) Handbook), and exam- 
ine the tip and adjacent 
) YY) i/ portion of one of the 
Nii young roots with a 
power of from twelve 
Ww to twenty diameters. 
‘Fic. 20.—Lengthwise Section (somewhat diagram- Note: 
matic) through Root-Tip of Indian Corn. x about 130. (a) The root-cap 
p] 
" W,root-cap ; i, younger part of cap; z, dead cells sepa- of loose ly 
rating from cap ; s, growing point ; o, epidermis oy ie attached Melia: 
intermediate layer between epidermis and central 
cylinder; p, central cylinder; d, layer from which (b) The central 
the root-cap originates. > cylinder. % 
- 11f the tradescantia or Zebrina cannot be obtained, roots of seedlings of 
oats, wheat, or barley, or of red-clover seedlings raised in a large covered cell 
on a microscope slide, may be used. 
